Even before I became a textbook author, I was party to more than one water cooler conversation about whether or not faculty should require students to purchase textbooks [viz.,http://tech.groups.yahoo.com/group/astrolrner/message/4958]. Now, that I am an introductory astronomy textbook author, I still feel the same way—there are some benefits to assigning a textbook to students and, more importantly, tremendous risks in not doing so.

Most folks who have moved away from textbooks entirely face a pretty serious problem in that the professor, and the professor’s notes, all too often can become the sole source of knowledge and expertise in the class. Sure studentsCAN go look up stuff and get another perspective, but my sense is that they don’t, and perhaps don’t even know how to do so effectively given the variety of presentations professors give. In the case where there is no clear supporting textbook readings assigned to students, the end result is an implicit and sizeable pressure on students—probably completely unintended by the professor— to memorize nearly everything that their professors say (or type onto aPowerPoint slide). It is these “memorized transcripts” that end up being what students are able to answer on exams. At the same time, a hidden social contract in the introductory astronomy class causes professors themselves to feel a sizeable pressure to only ask questions about what they specifically talk about in class. For my money, this is a LOSE-LOSE bet. When I consider all of this, it seems to me that the astronomy professor’s job should be about linking students’ thinking to the ideas of astronomy and giving students feedback about how well they are learning the concepts, not about being responsible for delivering astronomy ideas in their entirety.

Some folks have tried using trade books or coffee table books or extensive fact-based web sites. Although these are attractive, particularly in how they are illustrated, they lack the tried-and-true pedagogical tools that many, many students, publishers, and authors have worked through and tried to perfect over the years – explicitly stated learning goals, headings to structure student thinking, end of chapter summaries with review questions, and, gasp, even bold faced words to help focus student attention. I’m not saying that these things are perfect and are not often overused, BUT, what I would say is that these pedagogical clues are important enough to student readers that having them in a textbook is more important than the pretty pictures and pedagogy-free writing of coffee table books.

There is a dark side here, in that some students are preferentially disadvantaged more than other students when astronomy faculty purposefully choose not to assign readings connected to their teaching from a textbook—those are the students who already struggle with learning from your lecture. CAPER’s Stephanie J. Slater argues in Astrolrner Post #5014:

Stephanie Slater

Teaching using a textbook as a tool is pedagogical skill well worth learning. There is ample research out there that suggests that texts are important resources for many students, including those students who are most in need of extra help. Many students cannot take notes and listen to lecture at the same time. Students with specific learning disabilities, reduced working memories, who are second language learners, or who have poor spatial reasoning skills, struggle to glean concepts and facts from lecture. Non-text readings that are not structured with the coherence usually found in a textbook, or with the learning cues found in many texts, make life harder for our students who have ADD, reduced working memory, who are visually impaired, have visual-neurological dysfunction, or who have reduced access to technology.

So, for my money, I think using an astronomy textbook is an important part of the introductory science survey course. Yes, they can be expensive, but in the grand scheme of things that go into a college education, textbooks really aren’t. My most convincing evidence is that the $45 that students pay for theLECTURE TUTORIALS FOR INTRODUCTORY ASTRONOMY initially seems outrageous for a “work book” BUT, students rarely complain because they really, really use the book as part of their learning and they find it valuable. If students felt that the astronomy textbook helped them learn the material and they found it valuable, they wouldn’t care if it cost $235 (of course, if you haven’t looked at the half priced e-books or loose-leaf for students as an significantly lower cost option, you should talk to the next textbook sales representative that comes through the door – these lower-price alternatives are getting really attractive!).

I think the consistent problem that most astronomy faculty face related to textbooks is nothing short of simply OPERATOR ERROR. If professors never ask students to be responsible for learning from the textbook without the instructor repeating or, even worse, and I’ve seen it, reading from the textbook during lecture, then why would students ever think a textbook is valuable. This problem is much better documented in physics than astronomy, where too many physics professors don’t’ use the textbook for anything other than problems at the end of the chapter. Eric Mazur says that, even at Harvard, students won’t read unless you require it of them. My experience is that this applies no matter what your student demographic is. (I add this additional provocation for those who are about to say, “but my community college students couldn’t possibly read the book.” I don’t see any truly convincing evidence of this–readability on astronomy books show that many are purposefully done at pre-high school reading-level anyway.)

Speaking for a moment as a textbook author, one thing that I have definitely learned is that no textbooks end up being perfectly accurate – even after tens of people read and comment and carefully check the drafts. Errors do somehow frustratingly slip through the textbook creation process—and some faculty out there love to find and point out those errors! However, I’m absolutely sure that if 25 experts were to look at your PowerPoint slides and listen to your lectures, very few of any of us are error free in our presentations. Unless you’ve had 25 experts review your lectures, you’re probably guilty of giving out some misinformation. Textbooks at least have had some (gulp, a lot, usually) expert review. The other thing I’ve learned that I didn’t fully understand before is that modern textbooks have pedagogical tools, as mentioned above, that really do matter to novice readers. Websites, nor trade books, often have these things that really do help students learn the material more efficiently, particularly struggling ones.

My thinking is that students should be required to learn from the textbook and that portions of exams should be allocated to material from the textbook that isNOT specifically covered in lecture, but students are specifically made aware of what they are to learn. I don’t want to spend my valuable class time telling them facts they can read in a much more precise and attractive language than I can “say” during class time. This doesn’t mean that you should abdicate your responsibility to helping students learn—however, if you are only asking your students to memorize what you say in class, you are missing a grand opportunity to teach students how to find, understand, and internalize material on their own. And, for many of us, we hope that we are helping our students, at least a little bit, become more talented life-long learners.

Center for Astronomy & Physics Education Research

CAPER Team focuses on improving teaching and learning in Astronomy and the Earth Sciences through disicpline-based education research, astronomy curriculum development, and professional development workshops in Astronomy, Physics, Planetary Sciences, and the Geosciences.